Laughing As Exercise

Here's your nightly math! Just 5 quick minutes of number fun for kids and parents at home. Read a cool fun fact, followed by math riddles at different levels so everyone can jump in. Your kids will love you for it.

Laughing As Exercise

Did you ever wonder what your face has to do to laugh? It’s actually a lot of work, right? since almost every part of your face moves. Your face has about 43 “muscles,” those pieces of your body that stretch and scrunch up to move different parts of you. Some say it takes fewer of them to smile than to frown, so you might as well smile instead of walking around grumbling. But others say it’s more work to smile. So which is it? It turns out that it’s not so clear. For one thing, people have around 43 facial muscles, but can have up to 15 more than that or 15 fewer. And we know some people smile big and give lots of muscles a workout, while other people barely lift a lip. Someone did count out that you need at least 5 pairs of muscles, or 10 total, to raise the corners of your mouth. And if you’re laughing big, you’re using much more of your face than that — not to mention the rest of your body if you’re really rolling on the floor.

Wee ones: If someone’s telling jokes and you laugh at 7 of them and your friend laughs at 5 of them, who laughed at more jokes?

Little kids: If you smile, then frown, then smile and frown and keep going, what’s the 7th face you make? Bonus: What’s the 17th?

Big kids: If you use 40 out of 43 muscles to laugh but just 20 to smile, what’s the smallest possible number of muscles that do both? Bonus: If you use 20 of your 43 muscles to stick out your tongue and 30 to laugh, what’s the biggest possible number of muscles that you don’t use for either one?

Answers:Wee ones: You laughed at more.

Little kids: A smile, like all the odd numbers. Bonus: Also a smile, since it’s 10 faces later; you’ll do 5 more sets of smile-frown.

Big kids: 17, since there are only 3 out of those 20 muscles at most that can differ. Bonus: 13 muscles, if you use all 20 tongue-sticking ones to laugh, too.

And thank you Xanthe M. for this awesome topic!

About the Author

Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking while still in diapers, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.